There is known a semiconductor package in which a semiconductor chip (semiconductor element) is covered (encapsulated) with a resin-made encapsulating (sealing) material. The encapsulating material for the semiconductor chip is produced by molding a resin composition (pulverized resin composition) containing a curable resin through, e.g., a transfer molding method.
A process for producing a semiconductor encapsulating resin composition (resin composition) includes a kneading process of kneading a resin composition (a composition) containing plural kinds of pulverized materials. The kneading process is performed after the pulverized materials are mixed. In the kneading process, a kneading extruder such as a single-axis type kneading extruder having a casing and a screw provided in the casing, a double-axis type kneading extruder having a pair of screws, or the like is used (for example, see patent document 1). The casing and the screw(s) of the kneading extruder are constituted of a metallic material.
However, since the casing and the screw of the conventional kneading extruder such as described above are constituted of the metallic material, the conventional kneading extruder suffers from a problem in that metallic foreign substances (foreign metals) are produced from the casing and the screw(s) and then the metallic foreign substances are mixed into the resin composition. As a result, there is a case in that short circuit occurs when the semiconductor chip is encapsulated with the resin composition produced by the conventional kneading extruder.
Patent document 1: JP 2003-275555A